Incorrect Billing

I had a two years contract with VODACOM that was ending on 31 October 2014.<br> End October I went to settle the account and I requested them to discontinue the account at Savannah Mall.<br> I was requested to phone *** to request them to cancel. I did so and also send an SMS ON 05/11/2014.Then I ported my account to MTN because their Business rates are cheaper, and again this account was renewed over and over by VODACOM without my knowledge.<br> When the contract ends they renew without informing you and when you query it the give you an excuse that they have already send airtime making it difficult to cancel the contract. This time I wanted to make sure I get out and out for real.I got their last statement in November that shows R00 and took it as proof that the account is cancelled.I then started getting phone calls from them instructing me to pay an outstanding amount of R650.00.I gave the caller my story and she told me she was just demanding payment, I should complain at ***m, which I did again.In March I got an SMS from the VODACOM that I have been handed over to debt collection Agency. I then rep**** and inform them that I have got proof which is my previous account.